Improvement in op



P. BOBRINGBR. .0ptometer- No. 212,536. Paftent'ed Feb. 25,1819. y

Unrrrul PETER BOER'INGER, OF ST. PAUL, MINNESOTA.

IMPROVEMENT IN OPTOIVIETERS.

Specification forming part of Letters Patent No. 212,536, dated February25, 1879 application filed December 30, 1878.

ATo all whom 'it may concern.-

Be it known that I, PETER BOERINGER, of St. Paul, in the county otRamsey and State of Minnesota, have invented certain new and usefulImprovements in Optometers, which improvements are fully set forth inthe following specification and accompanying drawings, in which- Figurel is a perspective view, and Figs. 2 and 3 detached detail views, of theglass-holding plates, showing variations in their construction.

This invention relates to optometers or instruments for adaptingspectacleglasses of any kind to different sights; and consists in astandor frame, upon which are mounted two revolving disks, in which glassesof different focal power are held, as hereinafter set forth.

The invention further consists in making one or both of the disksadjustable, laterally, upon a graduated slide, whereby the glasses maybe adapted to persons of different widths between the eyes, and to guidethe optician in fittin g up the spectacles, as hereinafter set forth.

The invention further consists in making the disks in which the glassesare held removable, so that the same frame or stand may be employed fordifferent kinds of glasses, as hereinafter set forth.

The invention further consist-s in an adjustable graduatedreading-tablet, whereby the desired focal length may be obtained, ashereinafter set forth.

A is the standard or foot, upon which a bar, B, is mounted in anysuitable manner, but preferably by a swivel, a, so that it can be adjusted higher or lower, to give the instrument the proper inclination tothe light. Cl is a beam or bar running across thebar B, and connectedthereto by a set-screw, b, so that it can be set at any desired angle.One end of this bar, C1, is bent upward at right angles, as shown at C2,and provided with a pin, c, upon which two disks or plates, d e, aremounted, the former being fixed upon the pin c and arm O2, while thelatteris free to revolve. g is a spring, which serves to hold the disk eupon the piu c, and is provided with an extension, g1, having a point,h, which iit-s into small countersunk cavities at equal points in theface of the disk e, so that it may be held in position and yet befreelymovable by the exertion of a slight degree of force. z' i are a seriesof perforations cut through the disk e at equal distances apart, nearthe outer rim, and adapted to receive spectacle-glasses of increasing ordecreasing degrees of focal power. la is an opening, cut in one side ofthe stationary disk d, of a shape to coliform to one ofthe glasses, sothat all the glasses will be covered except the one coming beneath thisopening. m is a small perforation through the disk d, near the center,through which one of the numbers on the revolving disk e (see Figs. 2and 3) may be seen, to indicate the number of the glass appearing beforethe opening k.

G3 is an arm similar to G2, and arranged to slide upon the arm G1 by aslide, u, and provided with a piu, c', and two disks, d e', preciselylike disks d e, except that openings 7c and perforation m' will be onthe opposite side, or both sets toward the center, as shown. The glassesin both disks e e will be counter parts of each other.

The bar Cl will be graduated where the slide n passes over it, so thatthe optician may know at what distance the two disks are apart, toenable him to select a pair of frames of the right distance between theglasses, as hereinafter more fully explained.

D D are two pivoted slides or covers, adapted to be turned down over theopenings 7c It', so that one of the exposed glasses may be covered. Thisis frequently necessary to test the power of or the effect upon one eyeata time, or when it is required to adapt two dierent kinds of glassesto olle person. l

The method of using this instrument is as follows: The two disks e ewill be supplied with glasses of increasing or decreasing power, and setupon the pins c c', as described. The patient will then turn the disks euntil `the glasses which suit the eyes are brought before the openingsk, and the readingtablet E moved back and forth until the proper focusis found, or the reading-tablet set at some required dis tance, whichwill be ascertained by gradua tions upon the bar B, and then the disks erevolved until the proper pair of glasses isfound.

If the patient, however, requires a different glass for each eye, one ofthe slides D is turned down over the openin g c'and the opposite diskturned until the proper glass is found for that eye, and then the othercover D turned down to hide that glass, and the first cover D removedand the other disk revolved until a glass is found to suit the othereye. By this means the full effect ofthe glasses upon each eye can beobtained. The arm C3 and slide a will be then moved to the right or leftto adjust the glasses to correspond to the distance between the eyes.When these facts are ascertained, it is a very easy matter for theoptician to select a pa-ir of spectacles to suit the patient, both as tofocal power and distance between the eyes.

Fig. 3 shows a slight variation in the method of forming the disk e,being a combination ot' hard rubber and metal; but the operation is thesame.

The catches g g may be applied in any suitable manner to accomplish thesame resultviz., to hold the disks c in place, so that acertain degreeof force is used to revolve them.

Set-screws may be attached to the instrument, so that it may be clampedrigidly after the glasses are adapted, to prevent accidentaldisplacement before the optician has had an opportunity to select thespectacles.

The standard A may be made otl a sufficient length to en able thepatient to use it in a standing position; or it may be made adjustable,to be used either sitting or standing. It may also be mounted upon afolding base, so as to be folded up into a small compass for conveniencein transportation, or for traveling opticians.

One great advantage gained by this arrangement is that in cases where aglass is required for one eye of a different power from that requiredfor the other eye, the disks may be revolved independently of eachother, and both eyes fitted with no more trouble than is required to fitglasses of the same power for both eyes.

This apparatus is adapted to any kind of glasses, concave, convex,cylindrical, prismatic &c.

" 7rIhe lateral movement of the disks e may be accomplished by hinge,slide, or equivalen device.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. In an optometer, the arrangement of the spectacle-glasses radiallyupon or within revolving disks or carriers, which disks or carriers areadapted to rotate independently of each other, substantially as and forthe purposes set forth.

2. The combination and arrangement of the disks d e d c, one xed and theother movable, and provided with the perforations and numbers wherebyonly the required number of glass may be brought to view and the numberascertained, while the remainder of the glasses are covered,substantially as hereinbefore set forth.

3. The disks d c d e', arranged as described,

and made movable, whereby theyY may be adjusted to iit the distancesbetween the eyes of different patients, substantially as hereinbeforeset forth.

4. The arrangement upon the beam O1 of the graduations, whereby thedistance apart ofthe disks c c may be ascertained, in the manner and forthe purpose hereinbefore set forth.

f 5. The combination and arrangement of the arms G2 C3, spring-catches gg1, and disks c e', whereby the latter may be made removable,substantially as hereinbefore set forth.

6. rIhe bar B, provided with the graduations, in combination with theslidin g and folding reading-tablet E, arranged and operatingsubstantially as hereinbefore set forth.

7. The combination, with the disks c e d d, of the movable covers D D,in the manner and for the purposesubstantially as hereinbefore setforth.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

PETER BOERINGER.

Vitnesses GEORGE Bolsamania, C. N. WooDwARD.

